LinkoCare Life Sciences Advances Bioengineered Corneal Implant Made from Porcine Collagen to Restore Vision in Visually Impaired Patients

Tech Daily, Beijing, August 11th, by reporter Zhang Mengran — Researchers from Linköping University in Sweden and LinkoCare Life Sciences AB have jointly developed an implant made from collagen in pigskin that closely resembles the human cornea. In a pilot study, the implant restored vision in 20 patients with corneal diseases, most of whom were blind before receiving the implant. Published in *Nature Biotechnology*, this study offers hope to patients suffering from corneal blindness and low vision by proposing bioengineered implants as an alternative to human cornea transplantation.

The cornea is mainly composed of collagen. To create a substitute for human corneas, researchers used collagen molecules derived from pigskin, which were highly purified and produced under strict conditions for human use. The pigskin used is a byproduct of the food industry, making it easily accessible and economically advantageous. During the construction of the implant, the researchers stabilized the loose collagen molecules to form a robust and transparent material capable of withstanding handling and implantation into the eye. Donated corneas must be used within two weeks, whereas bioengineered corneas can be stored for up to two years before use.

Researchers have also developed a new minimally invasive method to treat keratoconus, a condition where the cornea becomes very thin and may lead to blindness. Currently, patients with advanced keratoconus require surgery to remove the cornea, replacing it with a donated cornea, which is sutured in place using surgical sutures. This surgery is invasive and can only be performed in larger university hospitals.

The new surgical method does not require sutures and can be performed with high-precision corneal incisions using advanced laser technology or manually with simple surgical instruments when needed. The method was first tested on pigs, and the results proved it to be simpler and safer than traditional corneal transplantation.

Surgeons in Iran and India have conducted a pilot clinical study using this surgical method and implant. Twenty individuals who were blind or nearly blind due to advanced keratoconus participated in the study and received the biomaterial implant. The surgery was complication-free, with rapid tissue healing; an 8-week treatment with immunosuppressive eye drops was sufficient to prevent rejection of the implant. A two-year follow-up of the patients indicated no complications during this period.

The results of the pilot clinical study showed that the thickness and curvature of the cornea returned to normal. The degree of vision improvement in participants was comparable to that after corneal transplantation using donated tissue. Before the surgery, 14 out of 20 participants were blind. Two years later, none of them were blind anymore. Three Indian participants who were blind before the study had nearly perfect vision after the surgery.

[Editor-in-Chief's Note]

If the human eye is compared to an optical camera, the cornea is the camera lens. Once the cornea has problems, it can only be replaced with a good lens to take clear pictures again. The biggest advantage of corneal transplantation is that the cornea itself does not contain blood vessels and is basically in an "immune privileged" position, resulting in a very high success rate for transplantation. However, traditional corneal transplantation is still an invasive surgery, requiring patients to take medication for several years. Moreover, the donors used for corneal transplantation come from others' donations, and those who have suffered from certain eye diseases are not suitable to donate. Nowadays, advancements in both corneal substitutes and transplantation methods have not only improved the safety of this surgery but also enabled more patients to receive transplants, thereby regaining their sight.